<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script type="text/javascript" src="./js/vue.js"></script>
</head>
<body>
<div id="sss">
    <span>{{msg}}</span>
    <!--v-on:缩写为@-->
<button @click="on">点击</button>

</div>
</body>
<script>
    let  sss=new Vue({
        el:"#sss",
        data:{
msg:"caicaica"
        },
        methods:{
            on(){
                //this表示vue对象
                this.msg="蔡徐坤"
            }
        }
    })
</script>
</html>